Concurrent optical network terminal simulation

ABSTRACT

Systems and techniques for concurrent optical network terminal simulation are described herein. A data packet may be received by an optical lint terminal. It may be determined that the data packet is associated with an optical network terminal simulation host. The data packet may be modified based on the determination. The modified data packet may be transmitted to a device.

TECHNICAL FIELD

This disclosure is generally related to computer networks and, moreparticularly, to optical network terminal simulation in passive opticalnetworks.

BACKGROUND

A computer network is a collection of interconnected computing devicesthat may exchange data a share resources. Computer devices on thecomputer network may communicate with each other using a system ofaddresses such as internet protocol (IP) addresses. Optical networks maytransmit information using signals generated by a laser establishing achannel between devices connected to the optical media. Networkproviders may wish to verify the operation of hardware and softwarecomponents of the optical network. Several optical network terminals(ONTs) may be placed on the network to test the operation of hardwareand software components of an optical line terminal (OLT).

SUMMARY

In general, this disclosure describes techniques that may provide aunified hardware path for simulated optical network terminal (ONT)traffic and production traffic on a passive optical network (PON). Amedia access controller of the PON may modify data packets associatedwith (e.g., received from, destined for, etc.) a simulated ONT so thatthe data packets appear as production packets to the hardware andsoftware components of the PON. The need for physical ONTs for eachservice (e.g., feature, component, etc.) on the PON may be reduced andmay improve the efficiency of testing the ability of the PON hardwareand software to handle an increased ONT load, additional services, andservice modifications.

In one example, this disclosure is directed to an optical line terminal(OLT) for optical network terminal (ONT) simulation. The OLT comprisesat least one processor, a transceiver, and a memory includinginstructions that, when executed by the at least one processor, causethe at least one processor to perform operations to receive, via thetransceiver, a data packet; determine that the data packet is associatedwith an ONT simulation host; modify the data packet based on thedetermination, and transmit, via the transceiver, the modified datapacket.

In another example, this disclosure is directed to at least one machinereadable medium including instructions for optical network terminal(ONT) simulation that, when executed by an optical line terminal (OLT),cause the OLT to perform operations to receive, via a transceiver, adata packet; determine that the data packet is associated with an ONTsimulation host; modify the data packet based on the determination; andtransmit, via the transceiver, the modified data packet.

In another example, this disclosure is directed to a method for opticalnetwork terminal (ONT) simulation. The method comprises receiving, by anoptical line terminal (OLT), a data packet; determining that the datapacket is associated with an ONT simulation host; modifying the datapacket based on the determination; and transmitting the modified datapacket.

BRIEF DESCRIPTION OF THE DRAWINGS

To easily identify the discussion of any particular element or act, themost significant digit or digits in a reference number refer to thefigure number in which that element is first introduced.

FIG. 1 illustrates an environment and system for concurrent opticalnetwork terminal simulation, according to various embodiments.

FIG. 2 illustrates an example of a downstream packet termination forconcurrent optical network terminal simulation, according to variousembodiments.

FIG. 3 illustrates an example of an upstream packet termination forconcurrent optical network terminal simulation, according to variousembodiments.

FIG. 4 illustrates an example of a raw send packet termination forconcurrent optical network terminal simulation, according to variousembodiments.

FIG. 5 illustrates a flowchart of an example of a method for concurrentoptical network terminal simulation, according to various embodiments.

FIG. 6 is a block diagram illustrating an example of a machine uponwhich one or more embodiments may be implemented.

DETAILED DESCRIPTION

Gigabit-capable passive optical networks (GPONs) are complex networkingsystems that may serve a large number of endpoints (e.g., opticalnetwork terminals (ONTs) using one or more optical line terminals(OLTs). An entity (e.g., network operators such as internet serviceproviders, device manufacturers such as OLT manufacturers, etc.) maywish to test network components to verify that the components arecapable of operating at a designated capacity (e.g., a certain number ofconnected subscriber ONTs, etc.) and that the components are capable ofprocessing an expected variety of network traffic (e.g., video packets,audio packets, configuration packets, etc.).

The entity may maintain a test network operating independently of aproduction network for testing the GPON components. However, maintainingtwo distinct networks may be inefficient as this may result in doubleoperating expenses (e.g., due to space, power, cooling, personnel,hardware, etc.) for the entity. In addition, as subscriber demand growsthe entity may have to scale its internal test environments to matchcustomer deployments. For example, on a GPON card with 4 GPON ports,this may mean deploying 64 ONTs for each GPON port resulting in thedeployment of 256 ONTs. In an OLT with two 4 port GPON cards, this maymean deploying 512 ONTs.

Deploying physical hardware to match customer configurations may be evenmore challenging with OLT platforms where as many as 20 cards may bedeployed each with 16 GPON ports and each GPON port capable of servicing128 ONTs where a total of more than 40,000 ONTs may be deployed in atest network. Building such a test system may cost more than $4 millionfor the ONT hardware, cables, power, and testing equipment. Problemsassociated with maintaining a distinct physical test network mayincrease as subscriber demand for high-speed network access grows.

Software simulated ONTs may be used to facilitate scalability testing.The software simulation may operate on the line card itself and mayallow large systems of ONTs to be created, updated, and deleted toensure robustness with larger deployments. Each ONT may have associatedservices/actions that may stress the software and hardware interfaces.However, the software may track the services in an internal databaserather than stressing the services with simulated traffic. Anotherproblem with software simulated ONTs is that it may burden the memoryand processor of a system under test which may deviate from anequivalent physical ONT. In addition, the software simulation may belimited to database configuration and no actual packet traffic may begenerated and no load may be added on the hardware equipment.

The present subject matter may provide a solution to the problemsassociated with maintaining a separate test network and with softwaresimulated ONTs for testing service scalability by using the hardwaredata path without requiring a unique ONT for each service. The presenttechniques may be deployed on a live passive optical network (PON)(e.g., both simulated and physical ONTs may exist at the same time onthe network). This may provide the entity with the ability to maintain asingle network rather than two distinct networks. Concurrent ONTsimulation may use a field-programmable gate array (FPGA) in a GPON cardto route packets in such a way that packets will appear to the systemsoftware to have been received from a physical ONT rather than asimulated ONT.

The present subject matter may offload the simulated ONTs to an externalserver rather than the local line card, which may result in a reductionin memory and processor utilization in the OLT. For example, a server(e.g., running a Linux application, etc.) may run an ONT management andcontrol interface (OMCI) client. When the OMCI client is activated, aphysical packet may be sent from the server to the GPON line card. Thispacket may reach the FPGA GPON MAC, which may convert the packet to looklike an upstream OMCI packet and may forward the packet to the systemsoftware. This may provide the system software with a packet that may beindistinguishable from a real packet to which it may respond. The FPGAGPON MAC may route the response from the system software back to theserver. The OMCI client may simulate a variety of traffic such as, forexample, a management information base (MIB) upload, a request for anOMCI download, a routine statistic update, etc. To add additionalsimulated ONTs, another OMCI client may be launched on the server. Forexample, a single server may run many clients. The ability to launchmultiple simulated ONTs on the server may provide a more efficient wayto stress the hardware and software interfaces of the GPON.

The present subject matter may support both physical ONTs and simulatedONTs on the same PON. The physical ONTs may be used to ensure thatreal-world services are not disrupted. Additionally or alternatively,physical ONTs may be used to test adding additional ONTs to a productionnetwork. By concurrently allowing simulated ONTs on the GPON withphysical ONTs, the entity may test adding additional clients that mayrequire software resources without having to install physical ONTs.Thus, the production network continues to operate with physical ONTswhile simulated ONTs are added to the network to verify hardware andsoftware interfaces (e.g., at higher capacity levels, with newfunctionality, etc.).

The OLT may process data packets to and from physical ONTs using normalPON termination. However, data packets corresponding to (e.g., destinedfor a simulated ONT, received from a simulated ONT, etc.) a simulatedONT may be further processed and modified so the data packets may betransmitted between the PON and the ONT simulation network. Toaccomplish this, the GPON MAC (e.g., included in a line card of the OLT,etc.) may perform multiple types of traffic terminations based on thedata packets received. For example, the GPON MAC may perform downstreamtermination (e.g., packets received at the GPON MAC that are supposed tobe transmitted to the GPON network). These packets may be modified andsent to the network uplink destined for the server.

In another example, the GPON MAC may perform upstream termination (e.g.,packets received at the GPON MAC from the server that are supposed to betreated as if they were received from the upstream GPON network). Thesepackets may be modified and sent to the upstream data path and may beprocessed as if they were received on the PON.

In another example, the GPON MAC may perform raw send termination (e.g.,software may source different types of messages to the ONTs). Somemessages transmitted to ONTs may be standard Ethernet frames and somemay be GPON specific messages such as physical layer operations,administration, and maintenance (PLOAM) messages and OMCI messages.These messages may be encapsulated as Ethernet frames before they aresent off the GPON line card to the servers. The messages may beencapsulated because, since they are specific to the GPON protocolstack, they may not contain proper Ethernet packet components.

While the provided examples discuss GPON, it will be understood that thepresent subject matter may be used in a variety of PONs such as, forexample, next generation passive optical network 2 (NG-PON2),10-gigabit-capable symmetric passive optical network (XGS-PON), Ethernetpassive optical network (EPON), etc. It may be noted that the benefitsof the present subject matter may increase as the ONT and servicecapacity of PONs increase.

FIG. 1 illustrates an environment 100 and system 105 for concurrentoptical network terminal simulation, according to various embodiments.The environment 100 may represent a passive optical network (PON). ThePON may conform to any of a variety of PON standards, such as thebroadband PON (BPON) standard (ITU G.983), the 1G Ethernet PON (EPON)standard, the 10G Ethernet PON (EPON) standard, the gigabit-capable PON(GPON) standard (ITU G.984), the 10-gigabit capable PON (XG-PON)standard (ITU G.987), or the 40-gigabit capable PON (NG-PON2) standard(ITU-T G.989) as well as future PON standards under development by theFull Service Access Network (FSAN) Group, ITU, IEEE, and otherorganizations.

The ITU-T B-PON G.983 standard is described in Recommendation ITU-TG.983.2, Series G: Transmission Systems and Media, Digital Systems andNetworks, Digital sections and digital line system—Optical line systemsfor local and access networks, “ONT management and control interface forB-PON,” July 2005.

The 1G EPON standard is described in IEEE Standard 802.3ah-2004-IEEEStandard for Information technology—Telecommunications and informationexchange between systems—Local and metropolitan area networks—Specificrequirements—Part 3: CSMA/CD Access Method and Physical LayerSpecifications Amendment: Physical Layer Specifications and ManagementParameters.

The 10G EPON standard is described in IEEE Standard 802.3av-2009-IEEEStandard for Information technology—Local and metropolitan areanetworks—Specific requirements—Part 3: CSMA/CD Access Method andPhysical Layer Specifications Amendment 1: Physical Layer Specificationsand Management Parameters for 10 Gb/s Passive Optical Networks.

The ITU-T GPON G.984 standard is described in Recommendation ITU-TG.984.1, Series G: Transmission Systems and Media, Digital Systems andNetworks, Digital sections and digital line system—Optical line systemsfor local and access networks, “Gigabit-capable passive optical networks(GPON): General characteristics,” March 2008.

The ITU-T XG-PON G.987 standard is described in Recommendation ITU-TG.987, Series G: Transmission Systems and Media, Digital Systems andNetworks, Digital sections and digital line system—Optical line systemsfor local and access networks, “10-Gigabit-capable passive opticalnetwork (XG-PON) systems: Definitions, abbreviations and acronyms,” June2012.

The ITU-T G.989 standard is described in Recommendation ITU-T G.989.1,Series G: Transmission Systems and Media, Digital Systems and Networks,Digital sections and digital line system—Optical line systems for localand access networks, “40-Gigabit-capable passive optical networks(NG-PON2): General requirements, March 2013.

The environment 100 may include a system 105 (e.g., an optical lineterminal (OLT) card, etc.) for implementing concurrent optical networkterminal (ONT) simulation. The system 105 may include a variety ofcomponents such as a switch 110 (e.g., a network switch), a GPON mediaaccess controller (GPON MAC) 115, and software 120. The switch 110 mayprovide a connectivity point for computing devices operating on networksoutside the GPON such as those providing network services 130. Theswitch 110 may be communicatively coupled to the GPON MAC 115. The GPONMAC 115 may provide a connectivity point for computing devices insidethe GPON. For example, the GPON MAC may include one or more GPON opticalinterface modules (GPON OIMs) 135 connecting the GPON MAC 115 to theoptical distribution network (ODN) 140 via physical optical media (e.g.,fiber optic cable, etc.). The switch 110 and the GPON MAC 115 may becommunicatively coupled to the software 120.

The software 120 may analyze incoming packets (e.g., using packetsniffing, traps, etc.) to determine a transmission, if any, to be sentin response to a received packet. The software 120 may include a varietyof services such as, for example, internet group management protocol(IGMP) proxy, domain host control protocol (DHCP), MAC-forced forwarding(MACFF), point-to-point protocol over Ethernet (PPPoE), etc. Forexample, a DHCP packet (e.g., a DHCP request) may be received by thesoftware 120 (e.g., via the switch 110) and the software may identifythe packet as a DHCP packet and may provide an appropriate DHCP response(e.g., host configuration information such as IP address, internetgateway, DNS server addresses, etc.).

The system 105 may manage the flow of data on a production network 125and a simulator network 180. The production network 125 may include oneor more physical optical network terminals (ONTs) 145 connected to theODN 140 that include one or more service clients 150. The one or moreservice clients may include for example, DHCP clients, PPPoE clients,set-top box (STB) emulator, etc. The GPON MAC 115 may receive trafficfrom the one or more physical ONTs 145 and may forward the traffic forexample to other physical ONTs or to a network services 130 server(e.g., via the switch 110). The system 105 may manage the flow of databetween the production network 125 and the simulator network 180 byproviding a hardware data path reducing (or eliminating) the need for aunique ONT for each service.

The simulator network may include one or more ONT client simulators 155(e.g., a server hosting simulated ONTs, etc.) and one or more ONTsimulation port 165 (e.g., physical ONT simulator, etc.). The one ormore ONT client simulator 155 may include a variety of simulated clients160 such as, for example, physical layer operations, administration, andmaintenance (PLOAM) clients, ONT management and control interface (OMCI)clients, session initiation protocol (SIP) clients, etc. The one or moreONT simulation ports 165 may provide emulated clients 170 such as, forexample, DHCP clients, PPPoE clients, STB emulators, etc.

Upon receiving a data packet, the GPON MAC 115 may analyze the datapacket to determine if the data packet is from or destined for a client(e.g., a simulated client 160 running on the one or more ONT clientsimulators 155, an emulated client 170 provided by the one or more ONTsimulation ports 165, etc.) on the simulation network 180. The GPON MAC115 may determine if the received data packet should be processed fordownstream termination (e.g., as described in FIG. 2), upstreamtermination (e.g., as described in FIG. 3), or raw send termination(e.g., as described in FIG. 4). During the processing the GPON MAC 115may determine that the data packet is from or destined for the client onthe simulation network 180. The GPON MAC 115 may modify the data packetso that a data packet from the client on the simulation network 180 maybe transmitted to a client on the production network 125 and so that apacket transmitted by a client on the production network 125 may betransmitted to a client on the simulation network 180. Thus, the GPONMAC 115 may make data packets sent to and from simulation clients toappear as production (e.g., non-simulated, from a physical ONT, etc.)data packets. Thus, a unified hardware data path may be provided forsimulated ONT traffic and production traffic. Therefore, the datapackets from the simulated ONTs will be processed as normal productiontraffic and may be able to stress the hardware and software componentsof the GPON to provide a more accurate test of the ability of the GPONto support additional ONT capacity and additional functionality. Usingthe unified hardware path may reduce the need for unique physical ONTsfor testing each service available on the GPON.

The present subject matter may be implemented in various configurations.For example, the switch 110, the GPON MAC 115, and the software 120 maybe implemented in different (or the same) computing systems (e.g., anOLT, a single server, a collection of servers, a cloud-based computingplatform, etc.). A computing system may comprise one or more processors(e.g., hardware processor 602 described in FIG. 6, etc.) that executesoftware instructions, such as those used to define a software orcomputer program, stored in a computer-readable storage medium such as amemory device (e.g., a main memory 604 and a static memory 606 asdescribed in FIG. 6, a Flash memory, random access memory (RAM), or anyother type of volatile or non-volatile memory that stores instructions),or a storage device (e.g., a disk drive, or an optical drive).Alternatively, the computing system may comprise dedicated hardware,such as one or more integrated circuits, one or more ApplicationSpecific Integrated Circuits (ASICs), one or more Application SpecificSpecial Processors (ASSPs), one or more Field Programmable Gate Arrays(FPGAs), or any combination of the foregoing examples of dedicatedhardware, for performing the techniques described in this disclosure.

FIG. 2 illustrates an example of a downstream packet termination 200 forconcurrent optical network terminal simulation (ONT), according tovarious embodiments. An optical line terminal (OLT) (e.g., using GPONMAC 115 as described in FIG. 1) may receive an incoming data packet 205.For example, the OLT may receive the data packet 205 from an Ethernetnetwork. Traffic may flow through the normal downstream processing path.At the end of downstream processing, a GPON emulation method portidentifier (GEM PID) lookup may occur. The OLT may complete a virtuallocal area network (VLAN) lookup 210 to determine if a VLAN (e.g.,identified using an stag field of the data packet 205, identified usinga ctag field of the data packet 205, etc.) included in the data packet205 maps to a GEM ID. At this point, the data packet 205 may beidentified for downstream termination (e.g., the data packet 205 isdestined for a simulation client on the simulation network 180 asdescribed in FIG. 1).

The OLT may internally loop the data packet 205 back to an upstream portand may insert two words of routing data. The first word of routing datamay be an IEEE 802.1Q VLAN that may route the modified data packet 240to a client simulation server (e.g., the one or more ONT clientsimulators 155 as described in FIG. 1). The first word of routing datamay include a tag protocol identifier (TPID) 245 and a VLAN ID (VID)250. The TPID may be a standard 802.1Q TPID (e.g., with a value of0x8100, 0x88a8, 0x9100). For example, the TPID may have a value of0x8100. The VID may be a standard 802.1Q VID. The VID may be a VLANrouting tag used to direct the modified data packet 240 to the clientsimulation server.

The second word of routing data may comprise a special EtherType and asixteen bit header. This sixteen bit header may contain a specific GPONport and GEM port ID associated with the modified data packet 240 whichmay allow the packet to be routed to the client simulation server. Thesecond word of routing data may include an EtherType (ETYPE) 255, apassive optical network (PON) 260, and a GEM ID 265. The ETYPE may be astandard IEEE 802.3 EtherType. For example, the ETYPE may have a valueof a local experimental value of 0x88b5 to denote the data packet 205 asa simulation ONT packet. The PON may denote from which PON (e.g., a PONof the ODN 140 as described in FIG. 1, etc.) the data packet 205originated. In an example, the PON may be a three bit value that mayallow up to 8 PON ports to use the same VID. The GEM ID may be astandard G.984.3 GEM Port ID. In an example, the GEM ID may be a twelvebit field that may allow a full GEM Port ID to reach a simulationclient. Once the modification to the data packet 205 has been completed,the modified data packet 240 may be transmitted to the simulation clientof the client simulation server.

FIG. 3 illustrates an example of an upstream packet termination 300 forconcurrent optical network terminal simulation, according to variousembodiments. An optical line terminal (OLT) (e.g., using GPON MAC 115 asdescribed in FIG. 1) may receive an incoming data packet 305. Forexample, the OLT may receive the data packet 305 from an Ethernetnetwork. The OLT may determine that the data packet 305 includes avirtual local area network identifier (VID). For example, the OLT maydetermine that the data packet 205 includes a VID indicating that thedata packet 205 has been received from a client simulation server (e.g.,the one or more ONT client simulators 155 as described in FIG. 1).

The OLT may identify an EtherType (ETYPE) 355 for the data packet 305.For example, the OLT may determine that the ETYPE 355 has a value of0x88b5. The OLT may decode the data packet 305 to determine a GPON portfor the data packet. For example, the OLT may use a passive opticalnetwork (PON) 360 value to determine the GPON port for the data packet305. The OLT may then modify the data packet 305 to remove the VID 350,ETYPE 355, PON 360, a tag protocol identifier (TPID) 345, and a GPONemulation method identifier (GEM ID) 365 from the data packet 305. Oncethe data packet 305 has been modified, the modified data packet 340 maybe transmitted to a client on the GPON (e.g., a client on the ODN 140 asdescribed in FIG. 1, etc.).

FIG. 4 illustrates an example of a raw send packet termination 400 forconcurrent optical network terminal simulation, according to variousembodiments. An optical line terminal (OLT) may transmit network passiveoptical network (PON) specific messages to optical network terminals(ONTs) on the PON. The messages may include OLT management and controlinterface (OMCI) messages that may provide configuration information tothe ONTs (e.g., firmware images, settings, etc.) and physical layeroperations, administration, and maintenance (PLOAM) messages (e.g.,low-level configuration messages for managing ONT hardware and firmwaresettings, etc.). Data packets for PON specific messages may lack thelayer 2 information used to transmit the messages outside of the PON. Inorder to transmit a PON specific message outside of the PON, the messagemay be encapsulated to provide the information used to transmit themessage outside the PON.

The OLT (e.g., using GPON MAC 115 as described in FIG. 1) may receive anincoming PON message 405. The OLT may modify the message 405 totransform it into a data packet 410 for transmission on a networkoutside the PON (e.g., the simulation network 180 as described in FIG.1). In an example, the OLT may add layer 2 header information to themessage. For example, the OLT may add a destination media access control(MAC) address and a source MAC address to the message. In some examples,virtual local area network (VLAN) tags may be added to the message. Oncethe message 405 has been modified, a data packet 410 may be transmittedto a client on the network outside the PON (e.g., a client simulationserver of the one or more client simulation servers 155 as described inFIG. 1).

The terminations described in FIGS. 2-4 may allow the OLT to passtraffic to and from the simulation network for processing as productiontraffic by the hardware and software components of the GPON. Themodifications to the data packets allow the simulated ONT traffic toshare a hardware data path with production network traffic. Thus, theneed to add unique physical ONTs for each service available on the GPONmay be reduced. Therefore, the hardware and software components may betested for capacity and service compatibility without adding additionalhardware components to the GPON which may result in more efficientnetwork testing.

FIG. 5 illustrates a flowchart of an example of a method 500 forconcurrent optical network terminal simulation, according to variousembodiments. The method 500 may provide similar functionality asdescribed in FIGS. 1-4.

At operation 505, an optical line terminal (OLT) (e.g., the system 105as described in FIG. 1) may receive a data packet. In an example, theOLT may include a passive optical media access controller (PON MAC)(e.g., the GPON MAC 115 as described in FIG. 1) and the data packet maybe processed (e.g., to make determinations about source and destinationof the data packet, etc.) by the PON MAC. In an example, the data packetmay be an Ethernet packet.

At operation 510, the OLT may determine that the data packet isassociated with (e.g., corresponds to, is destined for, is receivedfrom, etc.) an optical network terminal (ONT) simulation host (e.g., anONT client simulator 155 as described in FIG. 1, etc.). In an example,the OLT may determine that the data packet includes a passive opticalnetwork (PON) port identifier (PID) (e.g., a gigabit-capable PONencapsulation method PID, etc.) and may determine that the data packetis destined for the ONT simulation host using the PID. In an example,the OLT may identify that the data packet includes a virtual local areanetwork identifier (VLAN ID) and the OLT may determine an EtherType anda PON port for the data packet based on the VLAN ID. In an example, theOLT may determine that the data packet includes a PON specific message.In an example, the PON specific message may be an ONT management andcontrol interface (OMCI) message.

At operation 515, the OLT may modify the data packet based on thedetermination that the data packet is associated with to the ONTsimulation host. In an example, the OLT may modify the data packet toinclude a first word of routing data and a second word of routing data.In an example, the first word of routing data may include the VLAN ID.In an example, the second word of routing data may include a reservedEtherType and a designated header. In an example, the designated headermay include a PON port and the PID. In an example, the OLT may modifythe data packet by removing a VLAN ID, an EtherType, and a PON port fromthe data packet. In an example, the OLT may modify the data packet byencapsulating the data packet with a destination media access control(MAC) address and a source MAC address.

At operation 520, the OLT may transmit the modified data packet. Forexample, the modified data packet may be transmitted to the ONTsimulation host, a device on the PON, etc. In an example, the OLT maytransmit the modified data packet to the ONT simulation host using thefirst word of routing data and the second word of routing data. In anexample, the OLT may queue the modified data packet for transmission toa device (e.g., a physical ONT, hardware and software providing aservice, etc.) on the PON. In an example, the OLT may transmit themodified data packet over an Ethernet network. In an example, the OLTmay encapsulate the data packet and may transmit the encapsulated datapacket to the ONT simulation host. In an example, the OLT may transmitthe encapsulated data packet over an Ethernet network.

FIG. 6 illustrates a block diagram of an example machine 600 upon whichany one or more of the techniques (e.g., methodologies) discussed hereinmay perform. In alternative embodiments, the machine 600 may operate asa standalone device or may be connected (e.g., networked) to othermachines. In a networked deployment, the machine 600 may operate in thecapacity of a server machine, a client machine, or both in server-clientnetwork environments. In an example, the machine 600 may act as a peermachine in peer-to-peer (P2P) (or other distributed) networkenvironment. The machine 600 may be a personal computer (PC), a tabletPC, a set-top box (STB), a personal digital assistant (PDA), a mobiletelephone, a web appliance, a network router, switch or bridge, or anymachine capable of executing instructions (sequential or otherwise) thatspecify actions to be taken by that machine. Further, while only asingle machine is illustrated, the term “machine” shall also be taken toinclude any collection of machines that individually or jointly executea set (or multiple sets) of instructions to perform any one or more ofthe methodologies discussed herein, such as cloud computing, software asa service (SaaS), other computer cluster configurations.

Examples, as described herein, may include, or may operate by, logic ora number of components, or mechanisms. Circuit sets are a collection ofcircuits implemented in tangible entities that include hardware (e.g.,simple circuits, gates, logic, etc.). Circuit set membership may beflexible over time and underlying hardware variability. Circuit setsinclude members that may, alone or in combination, perform specifiedoperations when operating. In an example, hardware of the circuit setmay be immutably designed to carry out a specific operation (e.g.,hardwired). In an example, the hardware of the circuit set may includevariably connected physical components (e.g., execution units,transistors, simple circuits, etc.) including a computer readable mediumphysically modified (e.g., magnetically, electrically, moveableplacement of invariant massed particles, etc.) to encode instructions ofthe specific operation. In connecting the physical components, theunderlying electrical properties of a hardware constituent are changed,for example, from an insulator to a conductor or vice versa. Theinstructions enable embedded hardware (e.g., the execution units or aloading mechanism) to create members of the circuit set in hardware viathe variable connections to carry out portions of the specific operationwhen in operation. Accordingly, the computer readable medium iscommunicatively coupled to the other components of the circuit setmember when the device is operating. In an example, any of the physicalcomponents may be used in more than one member of more than one circuitset. For example, under operation, execution units may be used in afirst circuit of a first circuit set at one point in time and reused bya second circuit in the first circuit set, or by a third circuit in asecond circuit set at a different time.

Machine (e.g., computer system) 600 may include a hardware processor 602(e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 604 and a static memory 606, some or all of which may communicatewith each other via an interlink (e.g., bus) 608. The machine 600 mayfurther include a display unit 610, an alphanumeric input device 612(e.g., a keyboard), and a user interface (UI) navigation device 614(e.g., a mouse). In an example, the display unit 610, input device 612and UI navigation device 614 may be a touch screen display. The machine600 may additionally include a storage device (e.g., drive unit) 616, asignal generation device 618 (e.g., a speaker), a network interfacedevice 620, and one or more sensors 621, such as a global positioningsystem (GPS) sensor, compass, accelerometer, or other sensor. Themachine 600 may include an output controller 628, such as a serial(e.g., Universal Serial Bus (USB), parallel, or other wired or wireless(e.g., infrared (IR), near field communication (NFC), etc.) connectionto communicate or control one or more peripheral devices (e.g., aprinter, card reader, etc.).

The storage device 616 may include a machine readable medium 622 onwhich is stored one or more sets of data structures or instructions 624(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 624 may alsoreside, completely or at least partially, within the main memory 604,within static memory 606, or within the hardware processor 602 duringexecution thereof by the machine 600. In an example, one or anycombination of the hardware processor 602, the main memory 604, thestatic memory 606, or the storage device 616 may constitute machinereadable media.

While the machine readable medium 622 is illustrated as a single medium,the term “machine readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 624.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 600 and that cause the machine 600 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withsuch instructions. Non-limiting machine readable medium examples mayinclude solid-state memories, and optical and magnetic media. In anexample, a massed machine readable medium comprises a machine readablemedium with a plurality of particles having invariant (e.g., rest) mass.Accordingly, massed machine-readable media are not transitorypropagating signals. Specific examples of massed machine readable mediamay include: non-volatile memory, such as semiconductor memory devices(e.g., Electrically Programmable Read-Only Memory (EPROM), ElectricallyErasable Programmable Read-Only Memory (EEPROM)) and flash memorydevices; magnetic disks, such as internal hard disks and removabledisks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 624 may further be transmitted or received over acommunications network 626 using a transmission medium via the networkinterface device 620 utilizing any one of a number of transfer protocols(e.g., frame relay, internet protocol (IP), transmission controlprotocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards,peer-to-peer (P2P) networks, among others. In an example, the networkinterface device 620 may include one or more physical jacks (e.g.,Ethernet, coaxial, or phone jacks) or one or more antennas to connect tothe communications network 626. In an example, the network interfacedevice 620 may include a plurality of antennas to wirelessly communicateusing at least one of single-input multiple-output (SIMO),multiple-input multiple-output (MIMO), or multiple-input single-output(MISO) techniques. The term “transmission medium” shall be taken toinclude any intangible medium that is capable of storing, encoding orcarrying instructions for execution by the machine 600, and includesdigital or analog communications signals or other intangible medium tofacilitate communication of such software.

What is claimed is:
 1. An optical line terminal (OLT) for opticalnetwork terminal (ONT) simulation, the OLT comprising: at least oneprocessor; a transceiver; and a memory including instructions that, whenexecuted by the at least one processor, cause the at least one processorto perform operations to: receive, via the transceiver, a data packet;identify a passive optical network (PON) port identifier (PID) in thedata packet, wherein the PID is an emulation method port identifier;determine that the data packet is associated with an ONT simulationhost, wherein the ONT simulation host is a server device hosting asimulated ONT client from which the data packet originates; determinethe data packet is destined for the ONTO simulation host using the PID;modify the data packet based on the determination to alter acharacteristic such that the modified data packet indicates anorigination from a non-simulated ONT client rather than the simulatedONT client, wherein the modification includes addition of a first wordof routing data and a second word of routing data, wherein the secondword of routing data includes a designated header, and wherein thedesignated header includes the emulation method port identifier: andtransmit, via the transceiver, the modified data packet, wherein themodified data packet is transmitted to the ONT simulation host using thefirst word of routing data and the second word of routing data.
 2. TheOLT of claim 1, wherein the first word of routing data includes avirtual local area network identifier (VLAN ID).
 3. The OLT of claim 1,wherein the second word of routing data includes a reserved EtherType.4. The OLT of claim 3, wherein the designated header includes a PONport.
 5. The OLT of claim 1, wherein the instructions to determine thatthe data packet is associated with the ONT simulation host furthercomprise instructions that cause the at least one processor to performoperations to: identify a virtual local area network identifier (VLANID) in the data packet; and determine, in response to identifying theVLAN ID, an EtherType and a passive optical network (PON) port for thedata packet, wherein the instructions to modify the data packet includeinstructions to remove the VLAN ID, EtherType, and the PON port, andwherein the instructions to transmit the modified data packet includeinstructions to queue the modified data packet for transmission to adevice on the PON.
 6. The OLT of claim 1, wherein the instructions todetermine that the data packet is associated with the ONT simulationhost further comprises instructions that cause the at least oneprocessor to perform operations to: determine that the data packetincludes a passive optical network (PON) specific message; and identifythat the PON specific message is destined for the ONT simulation host,wherein the instructions to modify the data packet include instructionsto encapsulate the data packet with a destination media access control(MAC) address and a source MAC address, and wherein the instructions totransmit the modified data packet include instructions to transmit theencapsulated PON specific message to the ONT simulation host.
 7. The OLTof claim 6, wherein the PON specific message is an ONT management andcontrol interface (OMCI) message.
 8. The OLT of claim 6, wherein theinstructions to transmit the encapsulated PON specific message includeinstructions to transmit the PON specific message over an Ethernetnetwork.
 9. The OLT of claim 1, wherein the data packet is an Ethernetpacket.
 10. The OLT of claim 1, further comprising a passive opticalnetwork media access controller (PON MAC), wherein the instructions toreceive the data packet include instructions to process the data packetusing the PON MAC.
 11. At least one non-transitory machine readablemedium including instructions for optical network terminal (ONT)simulation that, when executed by an optical line terminal (OLT), causethe OLT to perform operations to: receive, via a transceiver, a datapacket; identify a passive optical network (PON) port identifier (PM) inthe data packet, wherein the PID is an emulation method port identifier;determine that the data packet is associated with an ONT simulationhost, wherein the ONT simulation host is a server device hosting asimulated ONT from which the data packet originates; determine the datapacket is destined for the ONT simulation host using the PID; modify thedata packet based on the determination to alter a characteristic suchthat the modified data packet indicates an origination from anon-simulated ONT client rather than the simulated ONT client, whereinthe modification includes addition of a first word of routing data and asecond word of routing data, wherein the second word of routing dataincludes a designated header, and wherein the designated header includesthe emulation method port identifier; and transmit, via the transceiver,the modified data packet, wherein the modified data packet istransmitted to the ONT simulation host using the first word of routingdata and the second word of routing data.
 12. The at least onenon-transitory machine readable medium of claim 11, wherein the firstword of routing data includes a virtual local area network identifier(VLAN ID).
 13. The at least one non-transitory machine readable mediumof claim 11, wherein the second word of routing data includes a reservedEtherType.
 14. The at least one non-transitory machine readable mediumof claim 13, wherein the designated header includes a PON port.
 15. Theat least one non-transitory machine readable medium of claim 11, whereinthe instructions to determine that the data packet is associated withthe ONT simulation host further comprises instructions that cause the atleast one processor to perform operations to: identify a virtual localarea network identifier (VLAN ID) in the data packet; and determine, inresponse to identifying the VLAN ID, an EtherType and a passive opticalnetwork (PON) port for the data packet, wherein the instructions tomodify the data packet include instructions to remove the VLAN ID,EtherType, and the PON port, and wherein the instructions to transmitthe modified data packet include instructions to queue the modified datapacket for transmission to a device on the PON.
 16. The at least onenon-transitory machine readable medium of claim 11, wherein theinstructions to determine that the data packet is associated with theONT simulation host further comprises instructions that cause the atleast one processor to perform operations to: determine that the datapacket includes a passive optical network (PON) specific message; andidentify that the PON specific message is destined for the ONTsimulation host, wherein the instructions to modify the data packetinclude instructions to encapsulate the data packet with a destinationmedia access control (MAC) address and a source MAC address, and whereinthe instructions to transmit the modified data packet includeinstructions to transmit the encapsulated PON specific message to theONT simulation host.
 17. The at least one non-transitory machinereadable medium of claim 16, wherein the PON specific message is an ONTmanagement and control interface (OMCI) message.
 18. The at least onenon-transitory machine readable medium of claim 16, wherein theinstructions to transmit the encapsulated PON specific message includeinstructions to transmit the PON specific message over an Ethernetnetwork.
 19. The at least one non-transitory machine readable medium ofclaim 11, wherein the data packet is an Ethernet packet.
 20. The atleast one non-transitory machine readable medium of claim 11, whereinthe OLT includes a passive optical network media access controller (PONMAC), and wherein the instructions to receive the data packet includeinstructions to process the data packet using the PON MAC.
 21. A methodfor optical network terminal (ONT) simulation, the method comprising:receiving, by an optical line terminal (OLT), a data packet; identifyinga passive optical network (PON) port identifier (PID) in the datapacket, wherein the PID is an emulation method port identifier;determining that the data packet is associated with an ONT simulationhost, wherein the ONT simulation host is a server device hosting asimulated ONT client from which the data packet originates; determiningthe data packet is destined for the ONT simulation host using the PID;modifying the data packet based on the determination to alter acharacteristic such that the modified data packet indicates anorigination from a non-simulated ONT client rather than the simulatedONT client, wherein the modifying includes adding a first word ofrouting data and a second word of routing data to the data packet,wherein the second word of routing data includes a designated header,and wherein the designated header includes the emulation method portidentifier; and transmitting the modified data packet, wherein themodified data packet is transmitted to the ONT simulation host using thefirst word of routing data and the second word of routing data.